224 THE DEVONIAN AND CARBONIFEROUS. (bull. 80. 



The Carboniferous rocks occur mainly in the southwestern part, along 

 Lime and Cascade Creeks and branches of Mineral Creek. These be- 

 loug to the Lower Carboniferous, and consist of argillaceous, arena- 

 ceous, and calcareous beds, having a thickness of some 1,200 feet, while 

 those of the Upper Carboniferous are made up of red sandstones, 2,000 

 feet in thickness. 



Mr. C. D. Walcott 1 reported identifications in the Grand Canon as 

 follows : 



In the Grand Caiion of Colorado is found the Red Wall limestone of 

 Gilbert forming the base of the Carboniferous series, and at the mouth 

 of the Kanab C anon about 1,000 feet of the Lower Aubrey sandstone 

 are well exhibited. Evidences of Devonian rocks were noted resting 

 upon the Tonto group (Cambrian), but in some places they were not 

 recognized at all, and where they were seen they did not exceed 100 

 feet in thickness. 



Mr. Frank Springer 2 reported that Burlington geologists, contrary 

 to the ideas of others, have been inclined to divide the Burlington lime- 

 stone into two parts upon paleontological evidence. This view is fur- 

 ther demonstrated by finding a similar occurrence in Lake Valley 

 mining district in New Mexico, tlius showing its extended range. 



Mr. A. C. Peale 3 in 1885 placed on record the first positive identifica- 

 tion of Devonian strata in the Rocky Mountain region of Montana. 

 Fossils were collected by the Hay den survey in 1872 from several locali- 

 ties in the Territory which Mr. Meek found to have a Devonian aspect, 

 but he regarded them as belonging to the Lower Carboniferous, as they 

 contained no strictly Devonian types of corals, crinoids, or lamelli- 

 branchs. The author visiting the region in 1884, in company with Dr. 

 Hayden, obtained a collection of fossils which he submitted to Mr. 

 Charles D. Walcott, 4 who identified them as undoubtedly Devonian. 



Mr. Walcott says : 



Of the twenty-three species of fossils given in lists 1 and 2, twelve are identical 

 with species occurring in the Upper Devonian of the Eureka district, Nevada. Of 

 the others, two are Upper Devonian species in New York State, and Athyris himuta 

 occurs at the base of the Carboniferous in the Eureka district. 



The remaining forms resemble closely those of the Lower Carbon- 

 iferous of the Eureka district. 



Mr. A. McCharles 5 gave account in 1887, of the occurrence of Devo- 



1 Walcott, Charles D. : Pre-Carboniferous strata in the Grand Canon of the Colorado, Arizona. Am 

 Jour. Sci., 3d ser., vol. 26, 1883, pp. 437-442, 484. 



* Springer, Frank : On the occurrence of the lower Burlington limestone in New Mexico. Am. 

 Jour. Sci., 3d ser., vol. 27, 1884, pp. 97-103. 



* Peale, A. C : Devonian strata in Montana. Science, vol. 5, 1885, p. 249. 



4 Two lists of the fossils prepared by him are given, including in the first, Discina lodensis Hall (t), 

 Streptorhynchus chemungensis Conrad, Orthis Vanuxemi (?) Hall (?), Chonetes mucronata Hall, Pro- 

 ductus speciosus, Spirifera disjuncta, etc., and in the second are Streptorhynchus chemungensis Conrad, 

 Bhynchonella Horsfordii Hall (?), etc. 



6 McCharles, A. : The footsteps of time in the Red River Valley, with special reference to the salt 

 spring and flowing wells to be found in it. Manitoba Hist, and Sci. Soc, Trans., No. 27, 1887, p. 18. 

 Description of occurrence of Archean, Ordoviciau, Silurian, Devonian, Cretaceous, and Quaternary, 



